GoldenAge
LadyHonoria - you're right, it's not healthy - there's lots of research into the damage to mental health caused by the sleeping patterns of shift workers. Essentially you should sleep when it's dark, and be be awake and functioning when it's light. Your body needs natural light and this last year when people have been without holidays in the sunshine has shown itself to have been damaging to our levels of vitamin D3. Advice given to clients - Prepare to go to bed at 1000 pm. No reading on or off a screen unless it's a paper back and something light - no thrillers. In bed at 11.00 with the light off. Set the alarm for 7 or 8. If you don't fall asleep, get up and walk about, then back to bed, repeat until you fall asleep. When the alarm goes off at 7 or 8 get up - even though you're tired, you must get up and do what you have to do - do not allow yourself to nap in the day and follow the same pattern as the previous day. In about four days you will be sleeping normally in the night and awake in the day. This change to your body rhythm is in your hands. Melatonin will help but you shouldn't take this unless you get it from your GP. Good luck.
I went to bed at 9 last night because I felt tired. I read for a while - I'm getting into the 'Golden Age' crime fiction of Ngaio Marsh so nothing demanding, and in paperback form. And as somebody else said about herself, as soon as I put the light out and my head hit the pillow I was wide awake. According to Xi Jinping (the Huawei fitness monitor round my wrist) I eventually dropped off at 3.49am and then slept soundly for 8 hours. There's nothing wrong with my actual sleep, it's getting to sleep at a sensible time that's the problem!